JP2019057608A - Coil component - Google Patents

Abstract

To provide a coil component capable of widening an allowable range regarding alignment while preventing variation in cubic volume of a magnetic gap from being considerably influenced by variation in alignment of a tabular core to a drum-shaped core.SOLUTION: A protrusively curved shape C1 is imparted to a top face 11 of first and second flanges 4 and 5 that are included in a drum-shaped core 3, in a view in an axial direction of a winding core part 2. In a location where an apex PK of the curved shape C1 is positioned, the top face 11 is closest with a lower principal surface 19 of a tabular core 18. The curved shape C1 acts in such a manner that a total cubic volume of a magnetic gap MG is kept constant even in a case where inclination of the tabular core 18 with respect to the flanges 4 and 5 is varied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil component, and in particular, a drum-shaped core having a winding core portion around which a wire is wound and first and second flange portions respectively provided at each end portion of the winding core portion, and The present invention relates to a coil component including a plate-like core passed between a first and a second collar.

  For example, Japanese Patent Application Laid-Open No. 2014-99857 (Patent Document 1) discloses an interesting technique for the present invention. Patent Document 1 describes a surface mount type coil component including a drum core and a plate core.

  The drum-shaped core has a core portion around which a wire is wound and first and second flange portions provided at respective end portions of the core portion. Each of the first and second flanges has an inner end surface facing the core portion and positioning each end of the core portion, an outer end surface facing the outer side opposite to the inner end surface, and an inner end surface and an outer side. The end face is connected to each other, and has a bottom surface directed toward the mounting substrate during mounting and a top surface opposite to the bottom surface.

  On the other hand, the plate-shaped core has a lower main surface and an upper main surface that face in opposite directions. The plate-like core is in a state of being passed between the first and second flanges, and in this state, the lower main surface is fixed to the drum-like core with the adhesive facing the top surface. .

  Patent Document 1 proposes a structure capable of obtaining a high adhesive strength between a drum-shaped core and a plate-shaped core in spite of a small amount of adhesive. More specifically, in the top surface of the collar portion, the central portion is the highest and forms a flat surface, and a gradient is formed so as to become lower from the central portion toward the end portion. As a result, the top surface of the buttocks and the lower main surface of the plate-shaped core are in direct contact with each other on the flat surface at the center of the top surface without using an adhesive, and from the end of the top surface to the center of the top surface Facing each other through a gap that gradually becomes narrower, and an adhesive is disposed in the gap. In the technique described in Patent Document 1, the gradient on the top surface of the buttock is given by an inclined plane.

  According to the technique described in Patent Document 1, since a capillary phenomenon can be caused on the central portion side of the top surface in the gap, the gap between the collar portion and the plate-like core is filled with a minimum amount of adhesive. Can do. Therefore, a relatively high adhesive strength can be obtained between the drum core and the plate core with a relatively small amount of adhesive.

JP 2014-99587 A

  In such a coil component, the plate core forms a closed magnetic circuit in cooperation with the drum core. In this closed magnetic path, the gap between the plate core and the drum core becomes a magnetic gap. Therefore, when the volume of the magnetic gap varies, the electrical characteristics of the coil such as inductance and impedance vary.

  In the coil component described in Patent Document 1, a flat surface is formed at the center of the top surface of the collar. The plate-like core is in direct contact with the collar portion at the flat surface, and forms a gap that gradually widens from the center to the end of the top surface of the collar. This gap becomes the magnetic gap described above.

  On the other hand, when manufacturing a coil component including a drum core and a plate core, a step of bonding the plate core to the drum core is performed. In this step, the plate core must be properly aligned with the drum core, but sometimes the plate core is brought into an incorrect position with respect to the drum core.

  In particular, in the case of the coil component described in Patent Document 1, a flat surface is formed in the central portion of the collar portion, and a gradient that becomes lower from the central portion toward the end portion is formed. In the step of adhering to the drum-shaped core, the plate-shaped core may be adhered to the drum-shaped core while the lower main surface thereof is inclined so as to be substantially parallel to the gradient surface of the flange portion. This causes a relatively large variation in the volume of the gap between the plate-shaped core and the flange, that is, the volume of the magnetic gap, and as a result, the electrical characteristics of the coil, such as inductance and impedance, vary greatly. It will be.

  Accordingly, an object of the present invention is to provide a coil component in which the variation in the alignment of the plate-shaped core with respect to the drum-shaped core does not greatly reflect the variation in the volume of the magnetic gap, and the allowable range for the alignment can be expanded. It is to do.

  The coil component according to the present invention is opposite to a drum-shaped core having a core part and first and second flange parts provided at opposite first and second end parts of the core part, respectively. A plate-shaped core having a lower main surface and an upper main surface facing in the direction, and at least one wire wound around the core portion.

  Each of the first and second flanges includes an inner end surface facing the core portion and positioning each end of the core portion, an outer end surface facing the outer side opposite to the inner end surface, and an inner end surface The outer end face is connected to each other, and has a bottom face directed to the mounting substrate side during mounting and a top face opposite to the bottom face.

  The plate-like core is fixed to the first and second collars with an adhesive with the lower main surface facing the top surface of the collar.

  In the coil component having such a configuration, in order to solve the technical problem described above, in the first aspect of the present invention, the top surfaces of the first and second flange portions are viewed in the axial direction of the core portion. The first curved shape has a convex shape, and the top surface and the lower main surface of the plate-like core are closest to each other at the position where the vertex of the first curved shape is located. .

  The first curved shape described above acts to keep the total volume of the magnetic gap substantially constant even when the inclination of the plate-shaped core with respect to the flange portion varies.

  When viewed from the top surface of the first and second collars toward the bottom surface, the first curved shape is preferably provided at least in a range where the core portion is located, and more preferably, the entire area of the top surface. Granted over. As described above, the first curved shape can extend the range of the inclination with respect to the flange portion of the plate-like core, which can keep the total volume of the magnetic gap substantially constant when applied over a wider range of the top surface. it can.

  It is preferable that the top surface and the lower main surface of the plate-like core form a minute gap through which the adhesive can permeate at a position where the vertex of the first curved shape is located. According to this configuration, since a magnetic gap is formed over the entire top surface, the magnetic flux is larger than when the top surface and the lower main surface of the plate core are in direct contact with each other. Can be suppressed, and the DC superposition characteristics can be improved.

  The dimension of the minute gap is preferably 1 μm or more and 3 μm or less.

  In the first aspect of the present invention, when viewed in the axial direction of the core portion, the first curved shape is an arc shape having a curvature radius r, and the curvature radius r is a plate shape viewed in the axial direction of the core portion. It is preferably larger than the width dimension W of the core. As described above, when the radius of curvature r of the arc giving the first curved shape is larger than the dimension W of the plate-like core as seen in the axial direction of the core, the magnetic gap due to the variation in the inclination of the plate-like core with respect to the flange portion. The fluctuation of the total volume can be made smaller.

  In the first aspect of the present invention, the top surface has a convex second curved shape when viewed in a direction in which the lower main surface of the plate-shaped core extends and is orthogonal to the axial direction of the core portion. It is preferable that In this way, in addition to the first curved shape on the top surface, the second curved shape is given, so that the region where the vertex of the first curved shape exists is specified in the thickness direction of the buttocks. It can be narrowed down to the position. As a result, the vertex of the first curved shape also becomes the vertex of the second curved shape.

  According to the above-described configuration, the first collar part and the second collar part with respect to the height dimension of the collar part corresponding to the distance between the top surface and the bottom surface of the collar part due to variations in manufacturing the drum-shaped core. Even if a difference arises between the two, the position at which the top surface of the buttocks and the lower main surface of the plate-like core are closest can be maintained at the apex of the first curved shape or in the vicinity thereof. Therefore, the length of the magnetic path formed in the drum-shaped core and the plate-shaped core can be kept substantially constant even if a difference in height occurs between the first collar and the second collar. Inductance variation can be suppressed.

  In the preferred embodiment described above, the vertex of the second curved shape is a surface parallel to the outer end surface, and is a position that is offset toward the outer end surface side from the surface passing through the midpoint of the line segment connecting the inner end surface and the outer end surface. More preferably. According to this configuration, even if the difference in height between the first and second collars becomes larger, the top surface of the collar and the lower main surface of the plate-like core are closest to each other. It is possible to maintain the position to be at the apex of the second curved shape or the vicinity thereof.

  Moreover, in this invention, the recessed part which surrounds and receives each top | upper surface of a 1st and 2nd collar part may be provided in the lower main surface of a plate-shaped core. According to this configuration, leakage of magnetic flux can be reduced, and as a result, inductance can be improved.

  In the first aspect described above, a convex curved shape is given to the top surfaces of the first and second collars, but the same shape is formed on the lower main surface side of the plate-like core facing the top surface. Even if is given, the same effect can be expected.

  That is, according to the second aspect of the present invention, in the second aspect, the lower main surface of the plate-like core has a convex curved shape when viewed in the axial direction of the core portion, and the apex of the curved shape is located. Is characterized in that the top surface and the lower principal surface of the plate-like core are closest to each other.

  According to the coil component according to the present invention, the curved shape is imparted to at least one of the top surface of the flange portion of the drum-shaped core and the lower main surface of the plate-shaped core, which are opposed to each other. Even if the inclination varies, the total volume of the magnetic gap can be kept substantially constant, and therefore, variations in inductance due to variations in the magnetic gap can be reduced.

  Further, in manufacturing the coil component, in the step of bonding the plate core to the drum core, the necessity of strictly managing the posture of the plate core with respect to the drum core is reduced. Therefore, the burden of process management is reduced, and as a result, the manufacturing cost of the coil component can be expected to be reduced.

The coil component 1 by 1st Embodiment of this invention is shown, (A) is a front view, (B) is a left view. FIG. 2 is a schematic diagram for explaining the fluctuation of the magnetic gap MG due to the inclination of the plate core 18 in the coil component 1 shown in FIG. 1. It is a left view equivalent to Drawing 1 (B) showing drum-like core 3a with which coil parts by a 2nd embodiment of this invention are provided. FIG. 7 is a view showing a coil component 1b according to a third embodiment of the present invention and showing a cross section corresponding to a cross section taken along line AA in FIG. 1B, and showing a wire wound around a core portion 2; Is omitted. FIG. 5 is a cross-sectional view similar to FIG. 4 for explaining the effect of the coil component 1 b shown in FIG. 4, (A) shows the coil component 1 b shown in FIG. 4, and (B) shows a conventional coil component 31. Show. It is a figure which shows the downward main surface 19c of the plate-shaped core 18c with which the coil components by 4th Embodiment of this invention are equipped. It is a left view equivalent to FIG.1 (B) which shows the coil components 1d by 5th Embodiment of this invention. It is a left view equivalent to Drawing 1 (B) showing coil component 1e by a 6th embodiment of this invention.

  A coil component 1 according to a first embodiment of the present invention will be described with reference to FIG. The illustrated coil component 1 constitutes, for example, a common mode choke coil.

  The coil component 1 includes a drum-shaped core 3 having a winding core portion 2. The drum-shaped core 3 includes first and second flange portions 4 and 5 provided at first and second ends opposite to each other of the core portion 2. The drum core 3 is made of an electrically insulating material, more specifically, a magnetic material such as NiZn ferrite, a metal amorphous material, or a resin containing magnetic powder. The core part 2 and the first and second flange parts 4 and 5 provided in the drum-shaped core 3 have, for example, a quadrangular prism shape having a substantially square cross-sectional shape.

  Each of the first and second flange portions 4 and 5 has an inner end surface 6 that faces the core portion 2 side and positions each end of the core portion 2, and an outer side that faces the outer side opposite to the inner end surface 6. And an end face 7. Each of the first and second flange portions 4 and 5 has first and second side surfaces 8 and 9 that connect the inner end surface 6 and the outer end surface 7 and face each other in opposite directions. . Further, each of the first and second flange portions 4 and 5 connects the inner end face 6 and the outer end face 7 and connects the first side face 8 and the second side face 9, It has a bottom surface 10 directed toward the mounting substrate during mounting and a top surface 11 on the opposite side of the bottom surface 10.

  In the illustrated embodiment, the inner end face 6 is parallel to the outer end face 7, but the inner end face 6 may be inclined with respect to the outer end face 7.

  Terminal electrodes 12 and 13 are provided on the bottom surface 10 of the first flange 4. Terminal electrodes 14 and 15 are provided on the bottom surface 10 of the second flange 5. The bottom surface 10 of each of the flange portions 4 and 5 forms a convex step at the position where the terminal electrodes 12 to 15 are provided.

  In FIG. 1A, the terminal electrodes 12 and 14 are positioned behind the terminal electrodes 13 and 15 so as to overlap the terminal electrodes 13 and 15, respectively. In FIG. And 15 are located behind the terminal electrodes 12 and 13 so as to overlap the terminal electrodes 12 and 13, respectively. In order to express this in the drawings, in FIGS. 1A and 1B, reference numerals attached to terminal electrodes positioned so as to overlap with each other are shown in parentheses.

  Normally, the terminal electrodes 12 to 15 are formed by baking a conductive paste. As an example, the terminal electrodes 12 to 15 are formed by applying a conductive paste containing silver as a conductive component and baking it at a peak temperature of 700 ° C.

  Instead of baking the conductive paste, the terminal electrodes 12 to 15 may be provided by bonding terminal fittings made of a conductive metal to the flanges 4 and 5.

  The terminal electrodes 12 to 15 are plated as necessary. As the plating, for example, an Ni plating film having a thickness of 3 μm and an Sn plating film having a thickness of 16 μm are sequentially formed by electrolytic plating, a Cu plating film having a thickness of 5 μm, an Ni plating film having a thickness of 3 μm, and a thickness of 16 μm. The Sn plating film is sequentially formed.

  For example, two wires 16 and 17 are spirally wound around the core portion 2 in the same direction. The wires 16 and 17 are made of, for example, copper wires insulated with polyurethane or polyesterimide. The wires 16 and 17 are wound, for example, for 30 turns, and are wound in multiple layers as necessary. A first end of the first wire 16 is connected to the terminal electrode 12, and a second end opposite to the first end of the first wire 16 is connected to the terminal electrode 14. A first end of the second wire 17 is connected to the terminal electrode 13, and a second end opposite to the first end of the second wire 17 is connected to the terminal electrode 15. For example, thermocompression bonding is applied to the connection between the terminal electrodes 12 to 15 and the wires 16 and 17. For thermocompression bonding, for example, a heating temperature of 510 ° C. is applied.

  The coil component 1 further includes a plate-like core 18 passed between the first and second flange portions 4 and 5. The plate-shaped core 18 forms a closed magnetic circuit in cooperation with the drum-shaped core 3. The plate-like core 18 is also made of an electrically insulating material, more specifically, a magnetic material such as ferrite, a metal amorphous material, or a resin containing magnetic powder, as in the case of the drum-like core 3. The plate-shaped core 18 has a lower main surface 19 and an upper main surface 20 that face in opposite directions. The plate-like core 18 is fixed to the flanges 4 and 5 with an adhesive 21 in a state where the lower main surface 19 faces the top surfaces 11 of the flanges 4 and 5. As the adhesive 21, for example, an adhesive made of a thermosetting epoxy resin is used, and the plate core 18 and the flanges 4 and 5 are fixed by hot pressing at 150 ° C. for 10 minutes.

  Next, a characteristic configuration of the coil component 1 will be described.

  When attention is paid to the top surface 11 of the first flange portion 4, as shown in FIG. 1B, a convex curved shape C1 is formed when viewed in the axial direction of the core portion 2. Therefore, the top surface 11 and the lower main surface 19 of the plate-like core 18 are closest to each other at the position where the vertex PK of the curved shape C1 is located. In this embodiment, the curved shape C <b> 1 has an arc shape and is provided over the entire top surface 11.

  Further, the top surface 11 of the first flange 4 and the lower main surface 19 of the plate-shaped core 18 form a minute gap OP through which the adhesive 21 can permeate at the position where the vertex PK of the curved shape C1 is located. Yes. According to this configuration, since the magnetic gap MG filled with the adhesive 21 is formed over the entire area of the top surface 11, the top surface 11 and the lower main surface 19 are in direct contact with each other at the closest point. Compared with the case where it exists, while being able to suppress the shift | offset | difference of magnetic flux, direct current | flow superimposition characteristics can be improved. The dimension of the minute gap OP is preferably 1 μm or more and 3 μm or less.

  The characteristic configuration on the first flange 4 side described above is also employed on the second flange 5 side.

  The curved shape C1 described above acts to keep the total volume of the magnetic gap MG substantially constant even when the inclination of the plate-like core 18 with respect to the flange portions 4 and 5 varies. This will be described with reference to FIG. FIG. 2 shows the coil component 1 from the same direction as in FIG. 1B, but the curvature of the curved shape C1 is greatly exaggerated. In FIG. 2, elements corresponding to the elements shown in FIG.

  2A shows a state in which the plate-shaped core 18 is fixed to the drum-shaped core 3 without tilting, and FIG. 2B shows a state in which the plate-shaped core 18 is tilted and fixed to the drum-shaped core 3. It is shown. In addition, the following description is given about the 1st collar part 4 side illustrated in FIG. Although the description is omitted, the same configuration as that of the first flange 4 side is realized on the second flange 5 side.

  Referring to FIG. 2, paying attention to the magnetic gap MG filled with the adhesive 21, the total volume of the magnetic gap MG is kept substantially constant even if the inclination of the plate-like core 18 with respect to the flange 4 varies. Can do.

  More specifically, in FIG. 2A, the magnetic gap MG has substantially the same volume on each side across the minute gap OP. On the other hand, as shown in FIG. 2B, when the plate core 18 is tilted to the right, the volume of the magnetic gap MG is closer to the left side of the minute gap OP than in the state of FIG. However, on the right side of the minute gap OP, the volume of the magnetic gap MG decreases. That is, as the volume of the magnetic gap MG increases on the left side of the minute gap OP, the volume of the magnetic gap MG decreases on the right side of the minute gap OP so as to compensate for it. The same can be said even when the plate-shaped core 18 is tilted to the left.

  From the above, if the curved shape C1 is given to the top surface 11 of the flanges 4 and 5 of the drum-shaped core 3, even if the inclination of the plate-shaped core 18 with respect to the flanges 4 and 5 varies, the magnetic gap MG The total volume of can be kept almost constant. Therefore, it is possible to reduce the inductance variation due to the magnetic gap MG variation.

  As described above, the effect that the total volume of the magnetic gap MG can be kept substantially constant even when the inclination of the plate-shaped core 18 with respect to the flanges 4 and 5 is varied is more reliable when the following condition is satisfied. To be demonstrated. That is, when viewed in the axial direction of the core 2, the curved shape C 1 is an arc having a radius of curvature r, and the radius of curvature r is the dimension W in the width direction of the plate core 18 as viewed in the axial direction of the core 2. (See FIG. 2 (A)). As described above, when the radius of curvature r of the arc that gives the curved shape C1 is larger than the width direction dimension W of the plate-like core 18 as viewed in the axial direction of the winding core portion 2, Variation in the total volume of the magnetic gap MG due to variation in inclination can be further reduced.

  Here, as an example, the height H of the curved shape C1 is preferably 2 μm or more and 10 μm or less, and the curvature radius r of the curved shape C1 is preferably 70 mm or more and 400 mm or less. At this time, the curved shape C1 is formed so that the adhesion between the plate-shaped core 18 and the flange portions 4 and 5 is good.

  Further, as described above, even if the inclination of the plate-shaped core 18 with respect to the flange portions 4 and 5 varies, the total volume of the magnetic gap MG can be kept almost constant, and therefore, the variation in inductance due to the variation in the magnetic gap MG. Can be reduced. Therefore, in manufacturing the coil component 1, in the process of bonding the plate core 18 to the drum core 3, the necessity of strictly managing the posture of the plate core 18 with respect to the drum core 3 is reduced. Therefore, the burden of process management is reduced, and as a result, a reduction in manufacturing cost of the coil component 1 can be expected.

  Next, a coil component according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a left side view corresponding to FIG. 1B of a drum-shaped core 3a included in the coil component according to the second embodiment. In FIG. 3, elements corresponding to those shown in FIG. 1B are denoted by the same reference numerals, and redundant description is omitted.

  In the drum-shaped core 3 shown in FIG. 1B, the curved shape C1 is applied over the entire top surface 11 as described above. As described above, the curved shape C1 is provided over a wider range of the top surface 11, and the range of the inclination with respect to the flanges 4 and 5 of the plate-like core 18 can keep the total volume of the magnetic gap MG substantially constant. Is preferable in that it can be widened.

  However, if the above-described advantages can be reduced to some extent, the curved shape C1 may be applied only to a part of the top surface 11 as shown in FIG. It may be given. In the drum-shaped core 3a shown in FIG. 3, the curved shape C1 has a range in which at least the core portion 2 is located when viewed from the top surface 11 to the bottom surface 10 of the first and second flange portions 4 and 5. In S.

  Also in the embodiment shown in FIG. 3, the range of the inclination of the plate-like core 18 (see FIG. 1) with respect to the flanges 4 and 5 that can keep the total volume of the magnetic gap substantially constant is not practically problematic. can do.

  Next, a coil component 1b according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a cross section corresponding to a cross section taken along line AA in FIG. 1B for the coil component 1b. In FIG. 4, illustration of the wire wound around the core portion 2 is omitted. In FIG. 4, elements corresponding to the elements shown in FIGS. 1A and 1B are denoted by the same reference numerals, and redundant description is omitted.

  The coil component 1b according to the third embodiment has the following characteristic configuration in addition to the characteristic configuration included in the first or second embodiment described above.

  The top surface 11 of each of the flange portions 4 and 5 provided in the drum-shaped core 3b is viewed in a direction in which the lower main surface 19 of the plate-shaped core 18 extends and perpendicular to the axial direction of the core portion 2. When a convex second curved shape C2 is applied. In order to distinguish the above-described curved shape C1 from the second curved shape C2, in the following description, the curved shape C1 is referred to as “first curved shape C1”.

  As described above, on the top surface 11, in addition to the first curved shape C1, the second curved shape C2 is given, so that the region where the vertex PK of the first curved shape C1 exists is shown in FIG. As shown in FIG. 3, the flange portions 4 and 5 are narrowed down to specific positions in the thickness direction. Therefore, the vertex PK is not only the vertex of the first curved shape C1, but also the vertex of the second curved shape C2.

  The effect produced by the second curved shape C2 will be described with reference to FIG. FIG. 5 is a cross-sectional view similar to FIG. 4, (A) shows the coil component 1 b shown in FIG. 4, and (B) shows a conventional coil component 31.

  Due to variations in manufacturing the drum-shaped core 3b, the height of the flanges 4 and 5 corresponding to the distance between the top surface 11 and the bottom surface 10 of the flanges 4 and 5 is the same as the first flange 4 and the second flange. There may be a difference with the collar 5. In FIG. 5A, the height dimension of the second collar part 5 is lower than the height dimension of the first collar part 4. Even in such a case, the position at which the top surface 11 of each of the flange portions 4 and 5 and the lower main surface 19 of the plate-like core 18 are closest is the vertex of the first and second curved shapes C1 and C2. It can be maintained at or near PK. Therefore, even if a difference in height occurs between the first flange 4 and the second flange 5, the length of the magnetic path formed in the drum core 3b and the plate core 18 is substantially constant. Can be maintained, and variations in inductance can be suppressed.

  In FIG. 5A, the height dimension of the second collar part 5 is lower than the height dimension of the first collar part 4, but conversely, The same applies to the case where the height dimension of the second flange portion 5 is higher than the height dimension.

  On the other hand, in the drum-shaped core 32 in the conventional coil component 31, a difference in height occurs between the first flange portion 33 and the second flange portion 34, for example, as shown in FIG. Thus, it is assumed that the height dimension of the second collar part 34 is lower than the height dimension of the first collar part 33. The top surface 35 of each of the flange portions 33 and 34 is not given any curved shape, and only a flat surface is formed.

  The conventional drum-shaped core 32 shown in FIG. 5B includes a core portion 36 that connects the flange portions 33 and 34 as in the case of the drum-shaped core 3b shown in FIG. ing. Each of the first and second flanges 33 and 34 includes, in addition to the top surface 35 described above, an inner end surface 37 that faces toward the core portion 36 and positions each end of the core portion 36. It has an outer end surface 38 that faces the outer side opposite to the inner end surface 37, and a bottom surface 39 that connects the inner end surface and the outer end surface and faces the mounting substrate side during mounting.

  On the other hand, the plate-shaped core 40 has a lower main surface 41 and an upper main surface 42 that face in opposite directions as in the case of the plate-shaped core 18 shown in FIG.

  In the conventional coil component 31 shown in FIG. 5 (B), the plate-like core 40 is passed between the first and second flange portions 33 and 34, and the lower main surface 41 is provided to each of the flange portions 33 and 34. When fixed to the flanges 33 and 34 via the adhesive 43 in a state of facing the top surface 35, the following state is brought about.

  The lower main surface 41 of the plate-shaped core 40 is closest to the top surface 35 at the ridge line portion R1 where the top surface 35 and the inner end surface 37 intersect with the first flange portion 33, and the second flange portion. 34, the ridgeline portion R2 where the top surface 35 and the outer end surface 38 intersect is in a state of being closest to the top surface 35. Therefore, the magnetic path passing through the vicinity of R1 on the first flange portion 33 side and passing through the vicinity of R2 on the second flange portion 34 side is the main one.

  On the other hand, although not shown, when there is no difference in height between the first flange portion 33 and the second flange portion 34, the lower main surface 41 of the plate-like core 40 has the first and second It will be in the state which approaches the whole surface of the top | upper surface 35 equally with respect to each of the collar parts 33 and 34. FIG. Therefore, the magnetic path passing through the vicinity of R1 described above is the main on both the first flange portion 33 side and the second flange portion 34 side.

  Therefore, the length of the magnetic path passing through the drum-shaped core 32 and the plate-shaped core 40 varies according to the difference in height between the first flange 33 and the second flange 34, and as a result, Variation in inductance occurs.

  In the third embodiment, as shown in FIG. 4, the apex PK of the second curved shape C2 is a surface parallel to the inner end surface 6 and the outer end surface 7 of each of the flange portions 4 and 5, There is also a feature that the position is shifted to the outer end surface 7 side from the surface MP passing through the midpoint of the line segment connecting the inner end surface 6 and the outer end surface 7. According to this structure, even if the difference in height between the first collar part 4 and the second collar part 5 becomes larger, the top surface 11 of the collar parts 4 and 5 and the plate-like core 18 The position closest to the lower main surface 19 can be maintained at or near the vertex PK of the second curved shape C2.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a view showing a lower main surface 19c of a plate-like core 18c provided for a coil component according to a fourth embodiment of the present invention.

  The fourth embodiment is characterized by the form of the plate-like core 18c. That is, the lower main surface 19c of the plate-shaped core 18c is provided with recesses 22 and 23 that surround and receive the top surface 11 (see FIG. 1) of each of the first and second flange portions 4 and 5. These concave portions 22 and 23 have an opening surface larger than the top surface 11 of each of the flange portions 4 and 5. According to this configuration, leakage of magnetic flux can be reduced, and as a result, inductance can be improved.

  In the illustrated plate-shaped core 18c, the above-described one concave portion 22 exclusively receives the first flange portion 4 and the other concave portion 23 exclusively receives the second flange portion 5, but two The recesses 22 and 23 may be replaced by a single recess that surrounds and receives both the first and second collars 4 and 5 together.

  In the embodiment described above, a convex curved shape is given to the top surfaces of the first and second collars. However, as shown in the embodiment below, the plate-shaped core facing the top surface Even if the same shape is given to the lower main surface side, the same effect can be expected.

  A fifth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a left side view corresponding to FIG. 1B, showing a coil component 1d according to a fifth embodiment of the present invention. In FIG. 7, elements corresponding to the elements shown in FIG. 1B are denoted by the same reference numerals, and redundant description is omitted.

  In the coil component 1d shown in FIG. 7, the lower main surface 19d of the plate-like core 18d has a convex curved shape C3 when viewed in the axial direction of the core portion 2 (see FIG. 1). As a result, the top surface 11 of the first collar 4 and the lower main surface 19d are closest to each other at the position where the vertex PK of the curved shape C3 is located. In this embodiment, the curved shape C3 has an arc shape and is provided over the entire area of the lower main surface 19d.

  Further, the top surface 11 of the first flange 4 and the lower main surface 19d of the plate-shaped core 18d form a minute gap OP through which the adhesive 21 can permeate at the position where the vertex PK of the curved shape C3 is located. Yes.

  Such a characteristic configuration on the first flange portion 4 side is also adopted on the second flange portion 5 side.

  Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a left side view corresponding to FIG. 1B or FIG. 7, showing a coil component 1e according to a sixth embodiment of the present invention. In FIG. 8, elements corresponding to those shown in FIG. 1B or FIG.

  In the coil component 1e shown in FIG. 8, as in the case of the fifth embodiment described above, the lower main surface 19d of the plate core 18d is convex when viewed in the axial direction of the core 2 (see FIG. 1). The curved shape C3 is formed. Further, in the coil component 1e, the top surface 11 of the first flange portion 4 has a convex curved shape C1 when viewed in the axial direction of the core portion 2 as in the case of the first embodiment described above. ing. Each vertex PK of these curved shapes C3 and C1 overlaps at the same position when viewed from the top surface 11 of the collar portion 4 toward the bottom surface 12. As a result, the top surface 11 and the lower main surface 19d of the plate-shaped core 18d are closest to each other at the positions where the respective vertexes PK of the curved shapes C3 and C1 are located.

  Further, the top surface 11 of the first flange 4 and the lower main surface 19d of the plate-shaped core 18d form a minute gap OP through which the adhesive 21 can permeate at the position where the apex PK of the curved shapes C3 and C1 is located. doing.

  Such a characteristic configuration on the first flange portion 4 side is also adopted on the second flange portion 5 side.

  While the present invention has been described with reference to the illustrated embodiment, various other modifications are possible within the scope of the present invention.

  For example, in the above-described embodiment, the coil components 1, 1b, 1d, and 1e constitute a common mode choke coil. However, they may constitute a single coil, and other transformers, baluns, etc. May be included. Therefore, the number of wires may be one or three or more, and the number of terminal electrodes provided on each collar can be changed accordingly.

  Further, in configuring the coil component according to the present invention, partial replacement or combination of configurations is possible between different embodiments described in this specification.

1, 1b, 1d, 1e Coil parts 2 Core parts 3, 3a, 3b Drum-like cores 4, 5 Gutter part 6 Inner end face 7 Outer end face 10 Bottom face 11 Top face 16, 17 Wire 18, 18c, 18d Plate-like core 19 , 19c, 19d Lower main surface 20 Upper main surface 21 Adhesive 22, 23 Recess C1, C2, C3 Curved shape PK Vertex OP Small gap

Claims (10)

A drum-shaped core having a core part and first and second flange parts respectively provided at opposite first and second ends of the core part;
A plate-shaped core having a lower main surface and an upper main surface facing in opposite directions;
At least one wire wound around the core, and
With
Each of the first and second brim parts has an inner end face that faces the core part and positions each end of the core part, and an outer end face that faces the outer side opposite to the inner end face, The inner end face and the outer end face are connected to each other, and has a bottom face directed to the mounting substrate side during mounting, and a top face opposite to the bottom face,
The plate-like core is fixed to the first and second flanges through an adhesive with the lower main surface facing the top surface,
The top surfaces of the first and second flange portions have a convex first curved shape when viewed in the axial direction of the core portion, and the apex of the first curved shape is located. The top surface and the lower main surface are closest to each other at a location,
Coil parts.   The first curved shape is imparted at least in a range where the core portion is located when viewed from the top surface to the bottom surface of the first and second collar portions. The coil component described.   The coil component according to claim 2, wherein the first curved shape is provided over the entire area of the top surface.   The top surface and the lower main surface form a minute gap through which the adhesive can permeate at a position where the vertex of the first curved shape is located. Coil parts.   The coil component according to claim 4, wherein a dimension of the minute gap is 1 μm or more and 3 μm or less.   When viewed in the axial direction of the core portion, the first curved shape is an arc shape having a curvature radius r, and the curvature radius r is the width direction of the plate-like core as viewed in the axial direction of the core portion. The coil component according to any one of claims 1 to 5, wherein the coil component is larger than a dimension W.   The top surface has a convex second curved shape when viewed in a direction in which the lower main surface extends and is orthogonal to the axial direction of the core portion. The coil component according to any one of the above.   The apex of the second curved shape is a surface parallel to the outer end surface, and is at a position offset toward the outer end surface side from a surface passing through a midpoint of a line segment connecting the inner end surface and the outer end surface. The coil component according to claim 7.   The coil component according to any one of claims 1 to 8, wherein the lower main surface of the plate-shaped core has a recess surrounding and receiving the top surface of each of the first and second flanges. A drum-shaped core having a core part and first and second flange parts respectively provided at opposite first and second ends of the core part;
A plate-shaped core having a lower main surface and an upper main surface facing in opposite directions;
At least one wire wound around the core, and
With
Each of the first and second brim parts has an inner end face that faces the core part and positions each end of the core part, and an outer end face that faces the outer side opposite to the inner end face, The inner end face and the outer end face are connected to each other, and has a bottom face directed to the mounting substrate side during mounting, and a top face opposite to the bottom face,
The plate-like core is fixed to the first and second flanges through an adhesive with the lower main surface facing the top surface,
The lower main surface of the plate-like core has a convex curved shape when viewed in the axial direction of the core portion, and the top surface and the lower main surface at a position where the apex of the curved shape is located. And are closest
Coil parts.

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